The present invention is directed to a slab or stripline laser that contains two electrodes and two resonator mirrors, whereby the electrodes define a discharge gap and form waveguide surfaces for the laser emission, and whereby the resonator mirrors immediately adjoin a first electrode. Such a stripline laser is disclosed by German Published Application 37 29 053. Both electrodes therein extend directly to the mirror and the electrical insulation between the two electrodes represents the mirror itself. As a result, the heat elimination in the mirror is affected and, thus obtainable power of the laser is limited.
U.S. Pat. No. 4,713,825 discloses that a CO.sub.2 waveguide laser be equipped with an optical bank of "Invar" rods and that the laser mirrors be secured to these. This structure requires adjustment devices for the laser mirrors and a minimum spacing of the mirrors from the waveguide in order to allow space for the temperature expansion of the waveguide.